1. Field or the Invention
The present invention relates to multiple circuit modules which are used in electronic devices such as high-speed digital computers of the type produced by Cray Research, the assignee hereof. Specifically, the present invention relates to an improved multiple circuit module which requires less force to assemble and reduces cross-talk between circuit paths.
2. Description of the Prior Art
Circuit boards are utilized in many types of electronic equipment and it is often necessary, particularly in complex equipment, to interconnect the circuit boards into a module, and to interconnect modules into multiple circuit modules. For example, high-speed electronic digital computers of the type produced by Cray Research utilize circuit modules consisting of four circuit boards mounted in close proximity on opposite sides of two cooling plates. Such circuit modules are arranged in banks and it is, therefore, desirable to interconnect adjacent circuit boards within a module in a manner which permits convenient disconnection for service and reconnection after service, and which also permits reversed stacking for testing.
One previously known example of an interconnected multiple circuit module is disclosed in U.S. Pat. No. 4,514,784 to Williams et al. In this apparatus, conductive pins were used to transmit signals from one circuit module to another. Electrical connection between the pins was accomplished by connector blocks positioned between the modules having bores defined therein for receiving the pins. This type of module connection was a great improvement over previous designs because it minimized twisting and misalignment of the connector elements, while facilitating connection over the shortest circuit paths.
However, as the architecture of high-speed electronic digital computers evolves, greater switching speed and circuit density are required. As circuit density increases, a greater number of connections are necessary between modules, thereby increasing the total force needed to connect the modules. In addition, as circuit density is increased, it becomes increasingly likely that induction caused by the transmission of a signal through a first circuit path will possibly affect the operation of an adjacent path. This phenomenon is known as cross-talk, and is a major impediment to improved circuit density in high-speed digital computers.
It is clear that there has existed a long and unfilled need in the prior art for an improved interconnected multiple circuit module which reduces the aggregate force necessary for assembly and disassembly, and which reduces inductive interference between adjacent circuit paths.